I've taken a month off twice in my career. It was truly refreshing. One of those times I did build a site that I brought to completion. It wasn't successful (I didn't really have a grasp on the promotion/marketing part of things) but it was rewarding to do. The other time I took a break for other reasons.
One benefit/consequence (depending on how you look at it) is that when you return to work (depending on where you are), you may find that it takes awhile for work to figure out how to re-integrate you into the workflow since they've kept rolling without you. In my instance, it made for a gradual re-adjustment back into the things, but it may not be what you want, and I suppose you also run the risk of a workplace deciding they can get by without you while you're gone.
One benefit/consequence (depending on how you look at it) is that when you return to work (depending on where you are), you may find that it takes awhile for work to figure out how to re-integrate you into the workflow since they've kept rolling without you. In my instance, it made for a gradual re-adjustment back into the things, but it may not be what you want, and I suppose you also run the risk of a workplace deciding they can get by without you while you're gone.